1. Field of the Invention
This invention relates to a double locking member for a connector, and more particularly to a structure which secondarily locks terminals in terminal accommodating chambers of a connector housing.
2. Related Art
A variety of techniques for secondarily locking terminals in a connector housing are known. FIGS. 5 and 6 show a conventional double locking member for a connector which is disclosed in Japanese Utility Patent Application (OPI) No. 97875/1991 (the term "OPI" as used herein means an "unexamined published application").
In FIG. 5, reference numeral 41 designates a connector; and 43, a plurality of terminal accommodating chambers having inlets 44. The connector 41 includes a housing 42 made of synthetic resin and having terminal accommodating chambers in which connecting terminals 36 and 37 are insertable through the inlets 44. The terminals are fixed in the terminal accommodating chambers 43.
Each of the connecting terminals 36 and 37 is formed by blanking a metal plate. The front end portion of each terminal is a contact portion 38 into which a mating pin contact (not shown) is insertable so that the pin contact is electrically connected to the terminal, and the rear end portion of each terminal is a crimping portion 39 which fixedly crimps a covered wire and its conductor. A guide protrusion 40 is formed on a part of the upper surface of the contact portion 38.
In the housing 42, the terminal accommodating chambers 43 are defined by top walls 45 and side walls 46. The top walls have guide grooves 47 and 48 extending end to end for guiding the connecting terminals 36 and 37. The guide grooves 47 and 48 are so arranged to ensure that the terminals are connected to the predetermined pin contacts.
In order to prevent the connecting terminals 36 and 37 from being inadvertently removed from the terminal accommodating chambers 43 in the rearward direction, as shown in FIG. 6, first locking members, namely, locking lances 49, are provided integral with the housing 42 and extend from the rear surfaces of the top walls 45 of the housing 42 obliquely forwardly in the terminal accommodating chambers 43. Therefore, the locking lances 49 abut the rear ends of the contact portions 38 of the connecting terminals 36 and 37 to retain the terminals. In addition, reference numeral 50 designates a suitable number of second locking members formed of an insulating material, namely, double locking members; and 52, a suitable number of inserting holes formed in the side walls 46 of the housing, extending from the side boards 51 of the housing 42 in a direction perpendicular to the longitudinal axes of the terminal accommodating chambers 43. The double locking members 50 are insertable into the inserting holes thus formed. The front end faces of the double locking member 50 are locking faces 53, which abut the rear ends of the guiding protrusions 40.
The above-described double locking members are elongated, and their first ends 50 are integrally connected to an end plate 54. A means for locking the double locking members 50 to the housing 42 may be designed as indicated by the double-dot chain line in FIG. 5. That is, the end plate 54 maybe locked with a hook-shaped flexible locking board 55 which is integral with the housing 42.
Another means for locking the double locking members is as shown in FIG. 7. That is, locking protrusions 56 are formed on the rear end faces of the double locking members 50. The locking protrusions 56 thus formed are locked to the side walls 46.
However, the above-described conventional double locking members suffer from the following difficulties. That is, in the case where the end board 54 is locked with the hook-shaped locking board 55 (see FIG. 5), the following difficulties are experienced. Since the locking board 55 protrudes from the side board 51 of the housing 2, the connector itself is unavoidably bulky. Further, the locking board 55 may be bent or broken by an external force attributable to the collision of some other member therewith, so that the double locking member may become disengaged.
In the case where the locking protrusions 56 are formed on the rear end faces of the double locking members 50, and the locking protrusion 56 thus formed are engaged with the side walls 46 (see FIG. 7), the locking protrusions 56 are forcibly engaged with the side walls. Hence, it is difficult to disengage the locking protrusions 56 from the side walls. Further, as the engagement and disengagement of the locking protrusions are repeatedly carried out, the locking protrusion 56 and the side walls 46 may be broken.
In view of the foregoing, an object of the invention is to provide a double locking member for a connector which will not be inadvertently unlocked by an external force, which is free from a difficulty that, even when the engagement and disengagement thereof are repeatedly carried out, the relevant members are not damaged, and which is not bulky.